Passage A Because dental caries (decay) is strongly linked to consumption of the sticky, carbohydrate-rich staples of agricultural diets, prehistoric human teeth can provide clues about when a population made the transition from a hunter-gatherer diet to an agricultural one.
Topic
The relationship between dental caries (cavities) and carbohydrate consumption — used as a clue to the transition from hunter-gatherer to agricultural diets.
Framework
Dual Passage. Both passages discuss the caries-agriculture link. Passage A presents the prevailing view (more agriculture = more caries) plus exceptions; Passage B applies that view to a specific archaeological site (Ban Chiang, Thailand) and finds an unexpected result.
Main Point
The prevailing view is that increased agricultural (carbohydrate-rich) diets cause more caries — but Passage B's Ban Chiang study found caries decreasing as agriculture increased, likely because the diet remained varied and shifted toward less cariogenic carbohydrates.
Passage A: The prevailing view, with exceptions
Caries strongly linked to sticky carbohydrates of agricultural diets. Leigh's North American study: meat-eating Sioux had almost no caries; maize-dependent Zuni had 75% caries — and But there are exceptions: nonagricultural populations eating processed acorn flour or wild plants high in cariogenic potential (Hopi pinyon nuts, wild tubers).
Passage B: Ban Chiang's anomaly
Ban Chiang, Thailand, transitioned from hunter-gatherer-cultivator to increasing agriculture over 2,000 years. Research generally says agricultural intensification declines health, including dental health. Caries is uncommon in pre-agricultural populations; tooth-wear (which removes fissures and reduces caries) is also a factor. Ban Chiang's diet included rice and yams from the start. Yet caries was slightly greater in the Early Group than the Late Group — opposite the expected pattern. Tooth-wear didn't explain it. Likely explanations: the late-period diet remained varied (no single food dominated), and there may have been a shift from yams (sweeter, more cariogenic) to rice (less cariogenic).